PSI - Issue 2_A

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 1912–1919 Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity Procedia 00 (2016) 000–000

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XV Portuguese Conference on Fracture, PCF 2016, 10-12 February 2016, Paço de Arcos, Portugal Thermo-mechanical modeling of a high pressure turbine blade of an airplane gas turbine engine P. Brandão a , V. Infante b , A.M. Deus c * a Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal b IDMEC, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal c CeFEMA, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal Abstract During their operation, modern aircraft engine components are subjected to increasingly demanding operating conditions, especially the high pressure turbine (HPT) blades. Such conditions cause these parts to undergo different types of time-dependent degradation, one of which is creep. A model using the finite element method (FEM) was developed, in order to be able to predict the creep behaviour of HPT blades. Flight data records (FDR) for a specific aircraft, provided by a commercial aviation company, were used to obtain thermal and mechanical data for three different flight cycles. In order to create the 3D model needed for the FEM analysis, a HPT blade scrap was scanned, and its chemical composition and material properties were obtained. The data that was gathered was fed into the FEM model and different simulations were run, first with a simplified 3D rectangular block shape, in order to better establish the model, and then with the real 3D mesh obtained from the blade scrap. The overall expected behaviour in terms of displacement was observed, in particular at the trailing edge of the blade. Therefore such a model can be useful in the goal of predicting turbine blade life, given a set of FDR data. 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy Behaviour of a crack in a corner or at a tip of a polygon-like particle Jan Klusák a, *, Ondřej Krepl a , Tomáš Profant b a CEITEC IPM, Institute of Physics of Materials Academy of Scie nces of the Czech Republic, Žižkova 22, Brno 616 62, Czech Republi c b Faculty of Mechanical Engineering, Brno University of Technology, Technická 2, 61669 Brno, Czech Republic Abstract Crack propagation in particle composite materials depends on the properties of a matrix and a particle. A changing combination of the materials of a matrix and a particle together with various shape of the particle can result either in an increase or decrease of global fracture properties of the composite. A crack propagating through a particle composite can be found in the following positions: (i) a crack with its tip in the matrix and approaching the particle, (ii) a crack with its tip at the matrix/particle interface, (iii) a crack passing through the particle (iv) a crack lying in the matrix/particle interface, (v) a crack with its tip in a corner or at a tip of a polygon-like particle. The stress state in the second and the last cases differs from the stress field of a crack in a homogeneous material. The last case can be simulated by means of a bi-material notch model. The model can be used for evaluation of toughening mechanisms of silicate based composites with various shapes of aggregates. The stress singularity exponents of the bi-material models are determined and analyzed for typical materials combinations and typical shapes of aggregates. As silicate based composites exhibit quasi-brittle behaviour, the stress field should be described in a larger area ahead of a crack tip. For this reason, the exponents of non-singular stress terms are analysed as well. Stress distribution in the vicinity of a crack tip is analysed and conditions for further crack propagation are estimated. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: Crack propagation, Composite materials, Silicate based composites, General singular stress concentrators, Generalized linear elastic fracture mechanics. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsib lity of the Scientific Committee of ECF21. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016.

Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +420-532290348. E-mail address: klusak@ipm.cz

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216© 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21.

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Peer review under responsibility of the Scientific Committee of ECF21. 10.1016/j.prostr.2016.06.240